Material delivery tension and tracking system for use in solid imaging

Abstract

A solid imaging apparatus and method employing a radiation transparent build material carrier and a build material dispensing system that accurately controls the thickness of the transferred layer of solidifiable liquid build material to the radiation transparent build material carrier to achieve high resolution imaging in three-dimensional objects built using an electro-optical radiation source.

1. A solid imaging system with a solidifiable liquid build material that layer-by-layer forms a three-dimensional object form cross-sectional data, comprising in combination:
 a. a frame; 
 b. a solidifiable liquid build material dispenser connected to the frame having an opening through which the build material is dispensed; 
 c. an endless flexible build material carrier rotatably mounted to the frame, the carrier having a first side and opposing second side between a first edge and an opposing second edge, the first side receiving liquid build material in a fluid wedge from the build material dispenser; 
 d. a radiation source mounted on the frame effective upon activation to selectively solidify the liquid build material; 
 e. a radiation modulating device to selectively illuminate pixels in each layer of the three-dimensional object to solidify the build material; and 
 f. build material carrier tensioning means mounted to the frame controlling the tension in the build material carrier as the build material carrier rotates about a predetermined path past the opening in the build material dispenser effective to control the fluid wedge so that less tension creates a thicker layer of build material received by the build material carrier and increased tension creates a thinner layer of build material received by the build material carrier. 
 
   
   
     2. The system according to  claim 1  further comprising the build material carrier being a flexible endless belt. 
   
   
     3. The system according to  claim 2  further comprising the flexible endless belt being radiation transparent. 
   
   
     4. The system according to  claim 3  further comprising a drive roller carriage pivotably mounted to the frame, the drive roller carriage having at least one drive roller mounted thereto and movable therewith, the drive roller being positioned at a distance on an opposing side of the frame to at least one idler roller, the build material carrier being rotatably mounted about the drive roller and the idler roller. 
   
   
     5. The system according to  claim 4  further comprising a plunger contactable with a pivot attachment and effective upon extension to move the attachment to extend or upon retraction to move the attachment to shorten the distance between the drive roller and the idler roller to thereby increase or decrease the tension on the build material carrier as it travels about its predetermined path. 
   
   
     6. The system according to  claim 5  further comprising the liquid build material dispenser having an elongated channel opening through which the build material is dispensed onto the first side of the build material carrier. 
   
   
     7. The system according to  claim 6  further comprising a tracking motor effective to offset the endless build material carrier as it travels about its predetermined path to center the build material carrier about the idler roller and drive roller. 
   
   
     8. The system according to  claim 7  further comprising opposing sensors adjacent the first edge and the second edge effective to sense an edge and activate the tracking motor to offset the build material carrier so the build material carrier tracks to center itself about the idler roller as it is driven by the drive roller when an edge is no longer sensed. 
   
   
     9. The system according to  claim 8  wherein the tracking motor causes the drive roller carriage to pivot about a second pivot point to cause the endless build material carrier to translate between the opposing sensors. 
   
   
     10. The system according to  claim 1  further comprising the radiation source emitting electro-optical radiation. 
   
   
     11. The system according to  claim 10  further comprising the radiation source emitting UV or visible radiation.